Essential Spectrum

Abstract

In this chapter we study various types of essential spectra of operators on a Banach space X. They are closely connected with the Calkin algebra \(
\mathcal{B}\left( X \right)/\mathcal{K}\left( X \right)
\)
, where \(
\mathcal{K}\left( X \right)
\)
denotes the ideal of compact operators.